Read the Yahoo guide to speed up your website, minimize HTTP Requests:
Visit this link- Yahoo site speed guide
The key topics for a faster website
According to Yahoo report : 80% of the end-user response time is spent on the front-end. Most of this time is tied up in downloading all the components in the page: images, stylesheets, scripts, Flash, etc. Reducing the number of components in turn reduces the number of HTTP requests required to render the page. This is the key to faster pages.